Concrete pan forms

ABSTRACT

A pan construction for concrete forming operations in which a mold formed and nestable skin or cover of pliable material that would otherwise be distorted by the weight of concrete being poured is maintained in place above form supports by a cellular core structure that may itself be shipped and handled in a compact relation. Wedge elements provide support for side walls of said pan cover. Core and pan removal are facilitated by use of materials having inherent or cooperative lubricity characteristics.

United States Patent Charlier et a].

[ CONCRETE PAN FORMS [72] Inventors: J. Edson Charlier, 1231 Jersey St., Denver, Colo. 80220; Elmer H. Schell, 3451 W. 94th St., Westminster, Colo. 80030 22 Filed: Sept. 9, 1970 211 Appl.No.: 70,708

52 05.0. ..249/175 511 int. Cl. ..B28b 7/28 [58] Field of Search ..249/175, 176, 122, 119-126, 249/142, 177, 183, 210, 212, 31,134,186, 46, 163, 165; 25/128 K, 128 RR [56] References Cited UNITED STATES PATENTS 1,892,31 1 12/1932 Macdonalcl ..249/177 X 3,503,583 3/1970 Jester ..249/176 3,543,458 12/1970 Guritz ..249/176 2,881,501 4/1959 Raney ..249/175 2,734,250 2/1956 Thompson ..249/177 X [4 1 Oct. 3, 1972 2,775,019 12/1956 Bemis ..249/176 X 2,823,442 2/ 1958 Miller ..249/31 X 3,109,217 11/1963 Kell ..249/176 3,317,178 5/1967 Kreier ..249/134 3,488,027 l/l970 Evans ..249/176 Primary Examiner.l. Spencer Overholser Assistant Examiner-John S. Brown Attorney-C. B. Messenger 5 ABSTRACT A pan construction for concrete forming operations in which a mold formed and nestable skin or cover of pliable material that would otherwise be distorted by the weight of concrete being poured is maintained in place above form supports by a cellular core structure that may itself be shipped and handled in a compact relation. Wedge elements provide support for side walls of said pan cover. Core and pan removal are facilitated by use of materials having inherent or cooperative lubricity characteristics.

2 Claims, 5 Drawing Figures PATENTEDnm m2 3.695.574

SHEET 1 UF 2 INVENTOR. J. EDSON- CHARLIER a By ELMER H. SCHELL T ATTOR'NEY PATENTEDnms m2 3.695574 sum 2 or 2 INVENTOR J. EDSON CHARLIER &

ATTORNEY CONCRETE PAN FORMS BACKGROUND OF THE INVENTION Previously many different pan forming systems have been proposed and used for the creation of voids in concrete construction. An industry-wide objective has apparently been the development of a pan form that is easy to handle and erect and that is also easy to remove once concrete had been formed thereabout. Certain lightweight types of pan forms have been developed utilizing metal, glass reinforced plastics or cardboard as the operative concrete contacting element or even as the support components thereof. Single pour useage, initial cost limitations, or bulk or handling disadvantages have limited the extent of use for previous systems. It is an object of the present invention to pro vide an improved pan forming system by providing components that avoid some of the earlier difficulties.

SUMMARY OF THE INVENTION Briefly stated, the present invention provides a pan form system in which the individual pans that areto be used to provide voids in poured concrete are made up of component elements inclusive of a cover or skin that is itself inherently pliable. The cover is not of adequate strength to withstand the weight of concrete to be poured, and accordingly a core structure is provided to fit within the skin or cover. The core structure is of cellular or lightweight construction, and it is engaged within the cover to provide weight withstanding support therefor. Side wedge elements efficiently transmit the load from the side walls of the cover to the core. The cover, the core and the wedges may be readily disassembled for shipment and handling in compact relationships. The pliable and flexible characteristics of the covers assure easy stripping of thepan molds.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective showing the components of a preferred embodiment of the invention with some parts broken away, 3

FIG. 2 is a perspective view of a complete unit with a corner broken away to show interior construction,

FIG. 3 is a perspective view of a wedge segment used in keeping with this invention,

FIG. 4 is a partial cross-sectional view taken through the cover only along the section line 4-4 of FIG. 2 showing further assembly details, and

FIG. 5 is a perspective view in partial section showing pan units made and used in accordance with this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the invention is shown in FIGS. 1-5. In FIG. 5 a plurality of pan units 11 are shown positioned for use in connection with the pouring of concrete floors. The separate pan units 11 are disposed on horizontal deck form elements 12 that are supported by beams 13 and shore components 14. The form work may be assembled and supported in any of the many different conventional or special forming systems so long as adequate support is provided for the deck 12. This deck, which preferably is of plywood, will then provide support for the individual pan units 11.

Each pan is positioned on the deck 12 with the flanges 16 of the pans being in direct contact with the deck. As shown, the flanges of adjacent pan units 11 may be in contacting relation, or the pan flanges may be separated by an additional space. The flanges and, accordingly, the pan units are held in their adjusted positions by application of a plurality of nails 17 that are driven into the deck along the free edges of the flanges 16 so that the head only will engage and hold the flange material. With this arrangement the separate pans can be readily removed from the deck pieces 12 after a concrete floor 18 has been poured and cured. The flanges are, accordingly, undamaged, and the pans can be reused many times. In actual construction operations the deck materials can be handled in large sheets. Usually the pan units will remain attached to such large sheet supports when the forms are to be moved to a new pour location.

In keeping with a major objective of the present invention, each pan unit is made up of separate elements, the further details of which are shown in FIGS. 14. In FIG. 1 a pan cover 21 is illustrated. This hollow structure has a flat surface 22 and tapered side walls 23, 24, etc. which are joined to the described flanges 16.'The pan cover 21 is preferably formed of a plastic material.

Since a further object of the present invention is to provide an overall system that is less costly than previous pan unit constructions, it is preferred that the pan cover 21 be formed of plastic sheet materials rather than of the glass reinforced type plastics. The pan cover 21 is preferably made of sheet materials, such as the polyethylene, polypropylene, vinyl and ABS sheet materials now becoming extensively available. The desirable sheet materials can be formed on drape molds or in cavity molds by the application of vacuum or through use of similar sheet forming techniques. A sheet material of a lesser structural rigidity can be used in the present system, since structural support elements are additionally provided that are adapted to be received in the pan cover 21.

Major support for the flat top 22 is provided by an open lattice or egg crate type supporting structure, such as the collapsible core 26. Core 26, which is preferably made of lightweight materials, has surrounding side walls 27 that enclose a lattice work of interconnecting separator pieces 28. These pieces 28 are, in the expanded condition, disposed at right angles one to the other and are interlocked each to each by a system of intersecting notches, etc. Preferably the sidewalls 27 and separator pieces 28 are all made of a corrugated board. Because of the nature of construction, the entire core assembly 26 may be collapsed into a folded relationship for more convenient handling. Core structures of similar construction have previously been found to be entirely satisfactory in the concrete forming industry.

The cores to be used in connection with the present invention are of different construction, however, than 7 those commonly used with previously used cardboard top 22, and it further serves as a pan cover support extending above the wedge pieces 32 that are disposed against the exterior surface of the core sidewalls 27. This double construction provides an economy benefit, since the wedge components would usually be formed of material that is more expensive than cardboard. Further, the wedge components are usually formed of materials that would provide little or no support for the pan cover 21 where the cross-sectional thickness of the wedge is of minor size.

The wedge elements 32 are preferably formed of a lightweight material that may be easily handled. Expanded styrene or urethane foam type materials have been found to be very satisfactory for this useage. The wedges have a wider base 33, and a back 34 and face 36 that converge toward the top 37. Since the sidewalls 27 of the core 26 are preferably upright, the angularity of the face 36 should conform to the angular disposition for the tapered sidewalls 23 and 24 for pan cover 21.

The wedges may be molded to the desired shape, or where an expanded type foam product is used, the individual wedges may be sawed from a block of material to obtain the desired shape. In addition to its lightweight advantages, the expanded foam materials provide a further advantage, inasmuch as they have a non-abrasive and, in fact, low friction exterior surface. The low friction and yielding surface makes it easy to remove the wedges and, in fact, the entire core assembly from the cover 21 after a floor has been poured. Where the wedges are sawed a dust of loosened materials generally remains on the surface, and this in itself tends to lubricate the cover to wedge face interface. This particular lubrication feature is especially benefcial when a concrete floor has been poured and the forms are then to be removed. After the form supports are themselves removed the support structure can be readily dropped away from the pan cover 21. Where the pan cover itself has an inherent surface lubricity characteristic, the cores are easily removed. The presence of the loosened materials of the wedges further facilitates this removal. The combination of an inherently flexible structure and a surface lubricity characteristic for the pan cover 21 materially improves the cover removal capabilities. The removability of the present system is further enhanced by the fact that in the described combination the pan cover has rounded corners at intersecting planes. This rounded structure provides a turret section of increased strength so that at such corners the pan cover itself is of adequate strength to withstand the pressures of poured concrete. When the turret section corners are of adequate strength, no portion of the core 26 or of the wedge elements 32 need be extended into the corners. The wedges are terminated away from the corners as shown in FIGS. 2 and 4, and the separator pieces 28 of the core are cut at an angle so that such pieces do not extend into contact with the rounded corners 31. The fact that the corners are of adequate strength to withstand the forces encountered and the fact that none of the supporting core elements or the wedges are engaged at the corners further facilitates removal of the support structure when the forms are being stripped. Where these support items do not extend to the corners, binding and entra ment of the forms is avoided.

or convenience in handling and useage, surfaces of the wedges are preferably scored as by the cuts 38. When the wedges are scored either by cutting or by mold indentation, a long strip of wedge material can be broken to a desired length at the job site.

We claim 1. A pan form system for the creation of voids in concrete floor construction between intersecting floor strengthening beams or ridges comprising a pan cover of external shape corresponding to features of the void to be provided in the concrete structure, said pan cover having top, side wall and flange surfaces disposed in intersecting relationships and rounded turret section transitional shapes at elevated corners of said pan cover, said pan cover being formed of plastic sheet materials of inadequate design strength to withstand the forces of poured concrete except at said rounded corners if unsupported, a core support structure for placement within said pan cover inclusive of a plurality of upright members disposed in intersecting relation for the laterally braced stabilization of said members when in use and for the support of the top surface of said cover, said pan cover sidewalls being angularly positioned laterally away from upright surfaces of said core support structure, and a plurality of wedge elements formed of a cellular lightweight plastics material disposed about upright members of said core support structure for contact with the angularly positioned sidewalls of said pan cover, said plastics material having a lubricity characteristic further enhancing removal of the entire core structure.

2. Structure as set forth in claim 1 wherein said wedge elements are laterally scored at positions along the length thereof to facilitate the breaking of said wedge elements into desired lengths. 

1. A pan form system for the creation of voids in concrete floor construction between intersecting floor strengthening beams or ridges comprising a pan cover of external shape corresponding to features of the void to be provided in the concrete structure, said pan cover having top, side wall and flange surfaces disposed in intersecting relationships and rounded turret section transitional shapes at elevated corners of said pan cover, said pan cover being formed of plastic sheet materials of inadequate design strength to withstand the forces of poured concrete except at said rouNded corners if unsupported, a core support structure for placement within said pan cover inclusive of a plurality of upright members disposed in intersecting relation for the laterally braced stabilization of said members when in use and for the support of the top surface of said cover, said pan cover sidewalls being angularly positioned laterally away from upright surfaces of said core support structure, and a plurality of wedge elements formed of a cellular lightweight plastics material disposed about upright members of said core support structure for contact with the angularly positioned sidewalls of said pan cover, said plastics material having a lubricity characteristic further enhancing removal of the entire core structure.
 2. Structure as set forth in claim 1 wherein said wedge elements are laterally scored at positions along the length thereof to facilitate the breaking of said wedge elements into desired lengths. 